Extension of the Coherence Time by Generating MW Dressed States in a Single NV Centre in Diamond

TL;DR

This paper demonstrates the generation of multiple dressed states in a single NV centre in diamond, significantly extending coherence time and enhancing quantum sensing sensitivity.

Contribution

It experimentally generates over four dressed states in a single NV centre and extends coherence time to approximately 1.5 ms, improving quantum sensing capabilities.

Findings

Extended coherence time to ~1.5 ms

Generated more than four dressed states

Achieved over tenfold sensitivity enhancement

Abstract

Nitrogen-vacancy (NV) centres in diamond hold promise in quantum sensing applications. A major interest in them is an enhancement of their sensitivity by the extension of the coherence time ($T_2$). In this report, we experimentally generated more than four dressed states in a single NV centre in diamond based on Autler-Townes splitting (ATS). We also observed the extension of the coherence time to $T_2 \sim$ 1.5 ms which is more than two orders of magnitude longer than that of the undressed states. As an example of a quantum application using these results we propose a protocol of quantum sensing, which shows more than an order of magnitude enhancement in the sensitivity.